Recently considerable efforts have been made in developing .alpha.-olefin polymerization catalysts of improved efficiency and sterospecificity as compared to conventional Ziegler-type catalyst systems. One such catalyst composition which has shown considerable promise, is the modified Ziegler catalyst disclosed in British Patent Specification No. 1,468,503. Specifically, the improved performance of this composition is attributable to a modification of the titanium trichloride component by reacting the titanium trichloride with phosphorus oxytrichloride at elevated temperatures, most preferably in the range from 80.degree. C. to 100.degree. C., in the presence of an aromatic hydrocarbon diluent, such as benzene, and in the absence of the organoaluminum component. It is disclosed that inferior results are obtained if other diluents such as aliphatic hydrocarbons are used.
Inasmuch as aromatic diluents such as benzene are highly toxic and flammable, the use thereof in the preparation of the modified titanium trichloride component at the required elevated temperatures, gives rise to a number of problems in maintaining a working environment wherein safety and health hazards are minimized.
It is, therefore, an object of the present invention to provide a process for the production of a phosphorus oxytrichloride modified titanium trichloride component of an olefin polymerization catalyst composition, wherein such hazards are significantly reduced.
Another object of the present invention is to provide an olefin polymerization catalyst composition containing a phosphorus oxytrichloride modified titanium trichloride component which catalyst exhibits improved efficiency and sterospecificity.
A further object is to provide a process for the production of an olefin polymerization catalyst wherein the energy requirements of the process are significantly reduced.
Still another object is to provide an olefin polymerization process of improved yield and polymer quality.
Further objects will become apparent from a reading of the detailed description of the invention and the appended claims.